Sole for iron golf club head

ABSTRACT

The invention creates a unique combination of head shape and surface friction coefficients that minimize the bad effects of turf impact. The invention is an iron-type golf club head having a body composed of a stainless steel material and having a front wall, a sole portion and an undercut recess. The sole portion extends rearward from the front wall and has a main surface, a stepped surface and an edge between the main surface and the stepped surface.

CROSS REFERENCES TO RELATED APPLICATIONS

The Present Application is a continuation application of U.S. Pat. No. 12/616503, filed on Nov. 11, 2009, which claims priority to U.S. Provisional Patent Application No. 61/117030, filed on Nov. 21, 2008, now abandoned, both of which are hereby incorporated by reference in their entireties.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an iron-type golf club heads. More specifically, the present invention relates to a new sole design for an iron-type golf club head to improve turf contact and divot taking.

2. Description of the Related Art

The prior art discloses sole designs for golf club heads.

The Golf club sole and the leading edge have meaningful effects on how well the club head maintains speed and direction. For many clubs and shots it is desirable to impact the ball just before the club down swing is complete, this to achieve improved spin for the situation. To achieve this, the club has to contact the ball and transfer energy to the ball near simultaneously with the turf. Should the club pass through the turf before the energy is transferred to the ball, the ball speed and spin are diminished.

Also, on contact with the turf, particularly in a downward hit, the impact can be felt as harsh by the golfer. Some golfers become timid about swinging the club toward the turf and attempt to pick the ball off the turf without contact. In general, a divot is taken to allow the club head to contact the ball in the most advantageous orientation. Contacting the ball just prior to the ground is the intent, but for most golfers there are errors in delivering the ball. It is preferable that the club head's path follow through the turf. Often the club head impacts the turf before the ball due to variation in the swing path and, or because the ball lies in the turf such that ball and turf must be hit for the most advantage. Event he best of players require this shot at times.

BRIEF SUMMARY OF THE INVENTION

The present invention resolves the problems of the prior art.

Golfers gain advantage by reducing variation of the ball flight. Executing the require swing and impact is necessary for the best results. There are variations in the swing and in the contact location of the club, ball impact. The mass properties of the club head are tailored to achieve the mass properties to minimize the impact of variations in the swing. Common faults and common expectations can be identified and details of the club design such as mass properties and the geometry of the head are used to better serve the identifiable segments. The mass properties designer to better an identified segment can be achieved in various geometries and constructions. These geometries also affect the many other properties of the club head. This invention enables the construction of club heads that simultaneously improve geometry driven mass properties, aesthetic appeal and forces during impact. Some of the impact forces degrade the head, ball impact orientation and speed Impact can also result in harshness felt in the golfer's hands.

The purpose of this invention is to minimize the impact variations, allow preferred geometries for specific mass properties, turf impact and functional and aesthetic appeal.

Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of an iron golf club head.

FIG. 2 is a perspective view of an iron golf club head.

FIG. 3 is a perspective view of an iron golf club head.

FIG. 4 is a perspective view of an iron golf club head.

FIG. 5 is a partial cross-sectional view of an iron golf club head.

FIG. 6 is a perspective view of an iron golf club head.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-10, an iron-type golf club head in accordance with the present invention is generally designated 20. The club head 20 is a cavity-back iron and includes a body 22 having a heel end 24 and a toe end 26. The body 22 has a front wall 28 for contacting a golf ball and a hosel 30 for receiving a shaft, not shown. In a preferred embodiment the golf club head 20 is composed of a stainless steel, however, those of ordinary skill in the art will appreciate that the golf club head 20 may also be composed of other materials, such as carbon steel, titanium, titanium alloy, zirconium or zirconium alloy.

The front wall 28 of golf club head 20 has a ball-striking surface 40 and a back surface 42. The ball-striking surface 40 has a plurality of scorelines 44 formed therein. In a preferred embodiment the top of the hosel 30 is lower than the toe end of the front wall 28, thereby lowering the center of gravity of the club head 20.

The golf club head 20 also has a top portion 46, a sole portion 48, a heel portion 50, a toe portion 52 and a rear surface 54. The top wall 46 extends rearward from the top end of the front wall 28, in a direction opposite the ball-striking surface 40, to the rear surface 54 of the body 22. The sole portion 48 extends rearward from the bottom end of the front wall 28 to the rear surface 54. The heel portion 50 extends rearward from the heel end 24 of the front wall 28 to the rear surface 54, and the toe portion 52 extends rearward from the toe end 26 of the front wall 28 to the rear surface 54. The rear surface 54, the top portion 46, the sole portion 48, the heel portion 50 and the toe portion 52 define an external rear cavity 56 in the body 22 of the club head 20. The top portion 46, the sole portion 48, the heel portion 50 and the toe portion 52 also provide the club head 20 with perimeter weighting to make the club head more forgiving and provide better performance for the typical golfer.

The golf club head 20 preferably includes an undercut recess 68 in communication with the external rear cavity 56. The undercut recess 68 preferably circumscribes the external rear cavity 56. Alternatively, the undercut recess 68 may extend along only a portion of the external rear cavity 56. A medallion, not shown, is preferably disposed in the external rear cavity 56 of the body 22.

As shown in FIGS. 1-6, the present invention creates a geometry that is aesthetically pleasing, consistent with the best mass properties and accommodating to the golfers interest in sole shapes that minimize interference between the turf and club head. This is accommodated by combining features of better player clubs and with improving player clubs. The radius of the face to sole transition is designed to be a smaller radius to maximize the extension of the flat face within the ball contact locations. Also the radius design penetrated the turf better than a more blunt face to sole transition.

The sole is extended away from the face to improve the mass properties of the center of mass, the mass distribution, appeal, and for clearance between the club head and the turf during the follow through of the swing. The sole is stepped such that the sole surface furthest from the face is raised away from the turf to minimize the turf contact through the swing particularly for the longer, less lofted “irons”. The surface friction is reduced by applying a thin dense chromium coating thorough electroplating.

The appeal of the step and associated geometry is detailed for both appearance and preferential shape.

The invention creates a unique combination of head shape and surface friction coefficients that minimize the bad effects of turf impact.

Further, this invention creates a geometry that is aesthetically pleasing, consistent with the best mass properties and accommodating to the golfers interest in sole shapes that minimize interference between the turf and club head. This is accommodated by combining features of better player clubs and with improving player clubs. The radius of the face to sole transition is designed to be a smaller radius to maximize the extension of the flat face within the ball contact locations. Also the radius design penetrated the turf better than a more blunt face to sole transition.

The sole is extended away from the face to improve the mass properties of the center of mass, the mass distribution, appeal, and for clearance between the club head and the turf during the follow through of the swing. The sole is stepped such that the sole surface furthest from the face is raised away from the turf to minimize the turf contact through the swing particularly for the longer, less lofted “irons”.

The step geometry is also aesthetically advantageous.

An iron-type golf club head in accordance with the present invention is generally designated. The club head is a cavity-back iron and includes a body having a heel end and a toe end. The body has a front wall for contacting a golf ball and a hosel for receiving a shaft, not shown. The hosel has a bore with an ingress opening and optionally an egress opening. In a preferred embodiment the golf club head is composed of a stainless steel, however, those of ordinary skill in the art will appreciate that the golf club head may also be composed of other materials, such as carbon steel, titanium, titanium alloy, zirconium or zirconium alloy.

The front wall of golf club head has a ball-striking surface and a back surface. The ball-striking surface has a plurality of scorelines formed therein. In a preferred embodiment the top of the hosel is lower than the toe end of the front wall, thereby lowering the center of gravity of the club head.

The golf club head also has a top wall, a bottom wall, a heel wall, a toe wall and a rear surface. The top wall extends rearward from the top end of the front wall, in a direction opposite the ball-striking surface, to the rear surface of the body. The bottom wall extends rearward from the bottom end of the front wall to the rear surface. The heel wall extends rearward from the heel end of the front wall to the rear surface, and the toe wall extends rearward from the toe end of the front wall to the rear surface. The rear surface, the top wall, the bottom wall, the heel wall and the toe wall define an external rear cavity in the body of the club head. The top wall, the bottom wall 48, the heel wall and the toe wall also provide the club head with perimeter weighting to make the club head more forgiving and provide better performance for the typical golfer.

From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims. 

I claim as my invention the following:
 1. An iron-type golf club head comprising: a body composed of a stainless steel material and having a front wall, a sole portion and an undercut recess, the sole portion extending rearward from the front wall and having a main surface, a stepped surface and an edge between the main surface and the stepped surface, wherein the sole portion has a length ranging from 7.5 cm to 10.0 cm and a width ranging from 1.0 cm to 4.0 cm, wherein the main surface has a width ranging from 1.0 cm to 2.5 cm, wherein the stepped surface has a width ranging from 0.25 cm to 1.5 cm, and wherein the edge has a height ranging from 0.3 cm to 0.5 cm.
 2. An iron-type golf club head comprising: a body composed of a stainless steel material and having a front wall, a hosel, a heel portion, a toe portion, a top portion, a sole portion and an undercut recess, the heel portion, the toe portion, the top portion and the sole portion defining an external rear cavity, the sole portion extending rearward from the front wall and having a main surface, stepped surface and an edge between the main surface and the stepped surface, wherein the sole portion has a length ranging from 7.5 cm to 10.0 cm and a width ranging from 1.0 cm to 4.0 cm, wherein the main surface has a width ranging from 1.0 cm to 2.5 cm, wherein the stepped surface has a width ranging from 0.25 cm to 1.5 cm, and wherein the edge has a height ranging from 0.3 cm to 0.5 cm. 